Fix heatmap issue and implement per round analysis

migrations/2024-10-06-171346_perround/up.sql

@@ -0,0 +1,10 @@
+-- Your SQL goes here
+CREATE TABLE IF NOT EXISTS demo_round (
+  demo_id bigint REFERENCES demo_info(demo_id),
+  round_number int2 NOT NULL,
+  start_tick bigint NOT NULL,
+  end_tick bigint NOT NULL,
+  win_reason TEXT NOT NULL,
+  events JSON NOT NULL,
+  PRIMARY KEY (demo_id, round_number)
+);